In general, approaches for charging a battery with power supplied from outside a vehicle are roughly classified into the approach that uses an in-vehicle charger mounted in a vehicle, and the approach that uses a stationary charging system located at a charging station or suchlike.
In the former of these approaches, the in-vehicle charger is connected to a household electrical outlet, and performs, for example, 100V AC to 200V DC conversion to charge the battery with a charging power of 200V DC at a relatively low speed.
On the other hand, in the latter approach, the stationary charging system performs, for example, 200V AC to 400V DC conversion to rapidly charge the battery with a charging power of 400V DC.
For example, a known stationary charging system includes a power unit 102, which consists of a single charging unit (CHG) 103, a control unit (MCU) 105 for controlling the charging unit 103, a first CAN communication line 106 for allowing data exchange between the control unit 105 and the charging unit 103, a second CAN communication line 107 for allowing data exchange between the control unit 105 and a vehicle via a charging gun (connector) 109, and an I/F portion 108, which consists of a liquid crystal touch panel for performing the operation of starting charge, etc., as shown in FIG. 5.
In the stationary charging system 100, the charging unit 103, which constitutes the power unit 102, converts alternating-current input power to direct-current charging power to be supplied to the vehicle via the charging gun 109.
Another known stationary charging system which includes a power unit consisting of a single charging unit is described in Patent Document 1.
Furthermore, in recent years, there is demand for increased output power for shorter charge time, and a known stationary charging system with increased output power has a power unit consisting of a plurality of charging units.
This stationary charging system uses charging power obtained by adding direct-current power outputs from the charging units, thereby realizing increased output power.